If by wet lifters you mean hydraulic lifters then maybe the crossover works. Since most hydraulics have a real RPM limit of 6500 there is no reason to have any issues.
I have yet to see any, as in not one single incidence of main bearings not getting oil. Ever. And I’ve knocked the rods out so many times I can no longer count it. And never once was a main bearing out of oil.
That’s the number one point to show it’s not a velocity issue. It can’t be. If the mains look fine and the rods are hanging out of the block, the mains got the oil and the rods didn’t. The mains oil first.